public class Main {
    public static void main(String[] args) {

            int a = 10;
            int b = 20;
            System.out.println("第一次调用方法之前");
            int ret = add(a, b);
            System.out.println("第一次调用方法之后");
            System.out.println("ret = " + ret);

            System.out.println("第二次调用方法之前");
            ret = add(30, 50);
            System.out.println("第二次调用方法之后");
            System.out.println("ret = " + ret);
        }

        public static int add(int x, int y) {
            System.out.println("调用方法中 x = " + x + " y = " + y);
            return x + y;
        }
    }


